How to check if a string contains only digits in JavaScript

In this Article we will go through how to check if a string contains only digits only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const isNumeric = str => !/[^0-9]/.test(str);

isNumeric(2);               // true
isNumeric('23');            // true
isNumeric('00123');         // true

isNumeric('1.23');          // false
isNumeric('-Infinity');     // false
isNumeric('Infinity');      // false
isNumeric('NaN');           // false